Display device with mitigated low frequency noise and operation method thereof

ABSTRACT

A display device can include a display panel including a plurality of pixels and touch electrodes configured to sense a touch input, and a timing controller configured to generate a vertical synchronization signal and a horizontal synchronization signal for controlling the display panel to display an image based on an image signal, and adjust the horizontal synchronization signal by varying a horizontal time period corresponding to a time period interval for individual cycles of the horizontal synchronization signal.

CROSS REFERENCE TO RELATED APPLICATION

The present application claims priority to Korean Patent Application No.10-2020-0186709, filed on Dec. 29, 2020 in the Republic of Korea, theentire contents of which are incorporated by reference into the presentapplication.

BACKGROUND OF THE INVENTION Field of the Invention

The present disclosure relates to a display device with mitigatedlow-frequency noise, and to an operation method thereof.

Description of the Related Art

With the advancement of an information-oriented society, various typesof display devices have been developed. Recently, display devices usingvarious techniques, such as a liquid crystal display (LCD), a plasmadisplay panel (PDP), and an organic light emitting display (OLED), havebeen commercialized.

In addition, as the display devices are employed in mobile products, thedisplay device can include a touch type input processing an operationdepending on a user's convenience and device characteristics.Accordingly, the display device can perform a display driving operationof displaying an image on a display panel and a touch driving operationof sensing the user's touch input.

As for a display device, there are an on-cell type display device inwhich a touch electrode for sensing the user's touch is directly formedon a display panel and an in-cell type display device in which a touchelectrode is formed in a display panel. In the on-cell type displaydevice, display driving and touch driving may be independently driven.In the in-cell type display device, a time-division driving method thattemporally divides a display driving section and a touch driving sectionmay be used.

In a time-division driving method, display driving and touch driving canbe driven by fixing and time-divisionally dividing a display drivingtime and a touch driving time during one frame at a constant ratio. Inthe time-division driving method, since the display driving time and thetouch driving time are fixed at the constant ratio, a signal isturned-on and turned-off in a constant cycle, and a generated frequencycomponent due to such a time-division driving method may act aselectromagnetic interference (EMI) noise or audible noise.

SUMMARY OF THE INVENTION

Electromagnetic interference (EMI) noise may be caused by a frequencycomponent that is generated as a horizontal synchronization (Hsync)signal determining a horizontal time 1H cycle is generated with a fixedcycle.

In order to mitigate such EMI noise, the present disclosure is intendedto propose a method of varying the horizontal time cycle for each lineand/or for each frame.

The technical problem and issues to be addressed by the presentdisclosure are not limited to the above-mentioned problem and issues,and other problems and issues that are not mentioned will be clearlyunderstood by those skilled in the art from the following description.

According to an embodiment of the present disclosure, a display deviceof the present disclosure includes a display panel including a pluralityof pixels arranged in a matrix form at intersection portions of aplurality of data lines and a plurality of gate lines and including atouch electrode for recognizing a touch input; a timing controllerconfigured to generate a control signal including a verticalsynchronization signal and a horizontal synchronization signal toprocess an image signal and a control signal that are received fromoutside and to output the image signal to the display panel; a datadriver configured to output a data voltage to each of a plurality ofdata lines of the display panel; a gate driver configured to output agate signal to each of a plurality of gate lines of the display panel;and a touch driver configured to provide a touch driving signal to thetouch electrodes of the display panel, in which the timing controllermay generate the horizontal synchronization signal such that ahorizontal time representing a time interval between the horizontalsynchronization signals is varied.

According to various embodiments of the present disclosure, a method ofoperating a display device including a display panel that includes aplurality of pixels arranged in a matrix form at intersection portionsof a plurality of data lines and a plurality of gate lines, a touchelectrode for recognizing a touch input, and a timing controllerconfigured to generate a control signal including a verticalsynchronization signal and a horizontal synchronization signal toprocess an image signal and a control signal that are received fromoutside and to output the image signal to the display panel, in whichthe method includes generating the horizontal synchronization signalsuch that a horizontal time representing a time interval between thehorizontal synchronization signals is varied.

Various methods proposed in the present disclosure have an effect ofmitigating low-frequency (EMI) noise caused by a display device (e.g.,by about 8 dB).

The effects that can be obtained from the present disclosure are notlimited to the above-mentioned effects, and other effects not mentionedherein will be clearly understood by those skilled in the art from thefollowing description.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objectives, features, and other advantages of thepresent disclosure will be more clearly understood from the followingdetailed description when taken in conjunction with the accompanyingdrawings, in which:

FIG. 1 is a view schematically illustrating a configuration of a displaydevice according to an embodiment of the present disclosure;

FIG. 2 is a view illustrating an operation example of a long horizontalblank (LHB) manner according to an embodiment of the present disclosure;

FIG. 3 is a view illustrating various examples of variably setting ahorizontal time according to embodiments of the present disclosure;

FIG. 4 is a view illustrating an example of generating the horizontaltimes having different periods from each other according to variousembodiments of the present disclosure;

FIG. 5 is a view illustrating a circuit related to generating ahorizontal synchronization signal for forming a variable periodhorizontal time according to various embodiments of the presentdisclosure;

FIG. 6 is a view illustrating examples of determining a horizontal timeperiod by a method other than using a horizontal time period register inFIG. 5 , in which the horizontal time period will be used in each MBsection according to an embodiment of the present disclosure; and

FIG. 7 is a view illustrating a method of generating the variable periodhorizontal time by a timing controller, according to various embodimentsof the present disclosure.

With regard to the description of the drawings, the same or similarreference numerals may be used for the same or similar components.

DETAILED DESCRIPTION OF THE EMBODIMENTS

In the following description of the embodiments and the drawings, thesame or similar elements are denoted by the same reference numeralsthroughout the specification. In addition, in the drawings, thethickness, ratios, and size of the elements may be exaggerated foreffective description of the technical details.

In this specification, it will be understood that when one component (orregion, layer, portion) is referred to as being “on,” “connected to,” or“coupled to” another component, it can be directlydisposed/connected/coupled on/to the one component, or an interveningthird component may also be present. Also, the terms “under,” “below,”“above,” “over,” “upper,” and the like are used for explaining relationassociation of components illustrated in the drawings. These terms arerelative concepts and are described based on the direction in thedrawings. It is to be understood that terms such as “including,”“having,” etc. are intended to indicate the existence of the features,numbers, steps, actions, elements, components, or combinations thereofdisclosed in the specification, and are not intended to preclude thepossibility that one or more other features, numbers, steps, actions,elements, components, or combinations thereof may exist or may be added.

The term “and/or” includes one or more combinations that the associatedelements may define. Terms “first,” “second,” etc. can be used todescribe various elements, but the elements are not to be construed asbeing limited to the terms. The terms are only used to differentiate oneelement from other elements. For example, the “first” element may benamed the “second” element without departing from the scope of theembodiments, and the “second” element may also be similarly named the“first” element. The terms of a singular form may include plural formsunless referred to the contrary.

In the following description of the embodiments of the presentdisclosure, a detailed description of known functions and configurationsincorporated herein will be omitted when it can make the subject matterof the present disclosure rather unclear. Further, the names of elementsused in the following description of the embodiments of the presentdisclosure are selected in consideration of ease of preparation of thespecification, and can thus differ from the names of parts of an actualproduct.

Hereinafter, various embodiments of the present disclosure will bedescribed in detail according to the order of the attached drawings. Allthe components of each display device according to all embodiments ofthe present disclosure are operatively coupled and configured.

FIG. 1 is a view schematically illustrating a configuration of a displaydevice according to an embodiment of the present disclosure.

Referring to FIG. 1 , a display device 100 according to the embodimentof the present disclosure can include a display panel 110, a gate driver120, a data driver 130, a timing controller 140, and a touch driver 150.

In the display panel 110, multiple pixels PXs are disposed. The pixelsPXs can be formed at intersection portions of gate lines GL1 to GLn anddata lines DL1 to DLm, where n and m can be positive numbers such aspositive integers. For example, the pixels PXs can be arranged in amatrix form on the display panel 110 that is a touch-integrated displaypanel.

Each pixel PX can be connected to the corresponding gate line GL1 to GLnand the corresponding data line DL1 to DLm. Such pixels PXs can emitlight with corresponding luminance depending on data signals that aresupplied to the data lines DL1 to DLm in synchronization with a supplytiming of gate signals supplied to the gate lines GL1 to GLn.

Depending on a type of the display device 100, the pixels PXs caninclude liquid crystals or light emitting elements (e.g., OLED's). Forexample, when the display device 100 is a liquid crystal display device,the display device 100 can include a light source (for example, abacklight unit). The light source can emit light to the display panel110, and each pixel PX can include a pixel electrode, a common electrodeCOM, and the liquid crystals. An electric field is formed between thepixel electrode and the common electrode COM in response to a datavoltage applied to the pixel PX. An arrangement of the liquid crystalcan be adjusted. Therefore, a transmittance of light emitted from thelight source is adjusted, so that each pixel PX can emit light withluminance corresponding to the data signal.

Otherwise, for example, when the display device 100 is an organic lightemitting display device (e.g., an OLED display device), each pixel PXcan include an organic light emitting diode. At this time, a drivingcurrent flowing to the organic light emitting diode is controlleddepending on a voltage of the data signal, so that each pixel PX canemit light with luminance corresponding to the data signal.

The gate driver 120, the data driver 130, and the timing controller 140can form a display driver of the display device 100.

The gate driver 120 is connected to the pixels PXs of the display panel110 through the gate lines GL1 to GLn. The gate driver 120 generates agate signal based on a gate driving control signal GCS output from thetiming controller 140. The gate driver 120 can provide the generatedgate signals to the pixels PXs through the gate lines GL1 to GLn.

The data driver 130 is connected to the pixels PXs of the display panel110 through the data lines DL1 to DLm. The data driver 130 can generatea data signal based on image data DATA and a data driving control signalDCS. An image data DATA and a data driving control signal DCS can beoutput from the timing controller 140. The data driver 130 can providethe generated data signals to the pixels PXs through the data lines DL1to DLm.

The timing controller 140 can generate the image data DATA, the gatedriving control signal GCS, and the data driving control signal DCS. Thetiming controller 140 can process an image signal and a control signal(for example, a horizontal synchronization signal (Hsync), a verticalsynchronization signal (Vsync), a main clock signal, and so on). Suchsignals can be received from outside to be suitable for operatingconditions of the display panel 110.

In the embodiment, the display panel 110 can be implemented as atouch-integrated display panel capable of sensing a touch input. To thisend, the display panel 110 can include multiple touch electrodes TEs.

The touch electrodes TEs can be disposed outside the pixel PX or can beembedded in a pixel cell. The touch electrodes TEs can be electrodesdisposed separately for touch sensing or can be electrodes used fordisplay driving. That is, any one of the electrodes of the pixel PXplaced for display driving can be used as the touch electrode TE.

For example, when the display device 100 is the liquid crystal displaydevice, the touch electrode TE can be the common electrode COM. Thecommon electrode COM can be embedded in the display panel 110. A commonvoltage Vcom is applied to the common electrode COM during displaydriving. Alternatively, when the display 100 is the organic lightemitting display device, the touch electrode TE can be one electrode(for example, a cathode electrode) of the organic light emitting diode.

Since the electrode used for the display driving also functions as thetouch electrode TE, display driving and touch driving can be temporallydivided.

In the following description, embodiments will be described with respectto a situation in which the display device 100 is implemented as theliquid crystal display device. However, the embodiments are not limitedthereto.

In an embodiment, the touch electrode TE can be configured in a sizecorresponding to the m pixels PXs grouped in units of blocks. Such touchelectrodes TEs can be implemented by dividing and patterning the commonelectrode COM into a size corresponding to the m pixels PXs. However,the embodiment is not limited thereto.

Each touch electrode TE is connected to the touch driver 150 through atouch line TL. Each touch electrode can sense an external touch input inresponse to a touch driving signal received from the touch driver 150.

The touch driver 150 is connected to the touch electrodes TEs throughthe touch lines TL. The touch driver 150 outputs the touch drivingsignal to the touch electrode TE. The touch driver 150 senses a touchinput by receiving a touch sensing signal from the touch electrode TE.In an embodiment, the display panel 110 can be configured to sense thetouch input by a self-capacitance method. In this embodiment, the touchdriver 150 can sense the touch input through a change in capacitanceidentified from the touch sensing signal.

The gate driver 120, the data driver 130, the timing controller 140, andthe touch driver 150 can be configured as separate integrated circuits(ICs), or ICs in which at least some portions thereof are integrated.For example, the data driver 130 can be configured as an integratedcircuit integrated with the timing controller 140 and/or the touchdriver 150.

In addition, in FIG. 1 , the gate driver 120 and the data driver 130 areillustrated as elements separated from the display panel 110. However,at least one among the gate driver 120 and the data driver 130 or bothcan be configured in an in-panel manner. By in-panel manner, such adriver can be formed integrally with the display panel 110. For example,the gate driver 120 can be formed integrally with the display panel 110according to a gate-in-panel (GIP) manner.

For a manner of temporally dividing display driving and touch driving, avertical blank (VB) manner and a long horizontal blank (LHB) manner canbe used.

FIG. 2 is a view illustrating an operation example of a long horizontalblank (LHB) manner.

Referring to FIG. 2 , the vertical synchronization signal (Vsync) is areference signal. The vertical synchronization signal can define oneframe time by temporally representing a start and an end of one screen.Accordingly, a start of the frame can be synchronized with a start ofthe vertical synchronization signal (Vsync). An end of the frame can besynchronized with a start of a next vertical synchronization signal(Vsync).

Multiple horizontal synchronization signals (Hsyncs) can be generated inone frame. The horizontal synchronization signal (Hsync) can be areference signal temporally indicating that one gate line is driven.Accordingly, one gate line can be turned-on at a start of the horizontalsynchronization signal (Hsync). The gate line can be turned-off at astart of a next horizontal synchronization signal (Hsync) and anothergate line can be turned-on. A section between the horizontal synchronoussignals Hsyncs can be referred to as a horizontal time 1H. Thehorizontal time 1H typically can have a constant value. That is, thehorizontal synchronization signal (Hsync) is generated in a constantcycle.

A touch-enable signal can be used to distinguish a display drivingsection and a touch driving section. According to an embodiment, asituation in which the touch-enable signal is high can be represented asthe touching driving sections T1 to T8. Also, a situation in which thetouch-enable signal is low can be represented as the display drivingsections D1 to D8. In contrast, a situation in which the touch-enablesignal is low can be represented as touch driving sections. A situationin which the touch-enable signal is high can be represented as displaydriving sections.

In FIG. 2 , a signal applied to the data line is represented as DL, asignal that appears on entire gate lines GL1 to GLn is represented asGate. A signal applied to the touch electrode TE is represented as TE.

As illustrated in FIG. 2 , in the LHB manner, the display drivingsections D1 to D8 and the touch driving sections T1 to T8 can appear inan alternating manner.

In the display driving sections D1 to D8, the gate signal Gate can beapplied to the gate lines GL1 to GLn in response to the horizontalsynchronization signal (Hsync). The data signal DL can be applied to thedata lines DL1 to DLm. In the touch driving sections T1 to T8, the touchdriving signal can be applied to the touch electrode TE.

The period for one display driving section and one touch driving sectioncan be referred to as 1 LHB section.

When the horizontal synchronization signal (Hsync) is generated in aconstant cycle as illustrated in FIG. 2 , electromagnetic interference(EMI) noise or audible noise may occur. Therefore, in order to mitigatethe EMI noise or the audible noise (e.g., a constant buzzing or hummingsound), a generation cycle of the horizontal synchronization signal(Hsync) can be varying. For example, the horizontal synchronizationsignal (Hsync) can be adjusted during one frame so that the Hsync signalis slight sped up for some portions of the frame and slightly sloweddown for other portions. According to an embodiment, the generationcycle of the horizontal synchronization signal (Hsync) can be setdifferently for each 1 LHB section within one frame. According toanother embodiment, the generation cycle of the horizontalsynchronization signal (Hsync) can be set differently for each frame.

FIG. 3 is a view illustrating various examples of variably setting thehorizontal time.

Referring to FIG. 3 , one frame section can be divided into N (forexample, N is eight) LHB sections, where N is a positive integer. EachLHB section can be formed of the display driving sections and the touchdriving sections. In the example in FIG. 3 , one frame is divided intoeight LHB sections. However, one frame is also possible to be dividedinto 12, 16, or more LHB sections.

Referring to the example in FIG. 3 , a period of a frame (e.g., oneframe period) can be divided into a plurality of periods (or horizontaltime) of LHBs. For example, the horizontal time for one LHB sectioncorresponds one display cycle (e.g., D1) and one touch cycle (e.g., T1),during which a number of gate lines are controlled based on the Hsyncsignal. According to one embodiment, the period of a LHB is setdifferent than the period of another LHB. According to an embodiment, inan LHB #1 section of a frame #1, a horizontal synchronization signal canbe generated such that a horizontal time of VH1_1 period is generated.In an LHB #2 section of the frame #1, a horizontal synchronizationsignal can be generated such that a horizontal time of VH1_2 period isgenerated. In an LHB #3 section of the frame #1, a horizontalsynchronization signal can be generated such that a horizontal time ofVH1_3 period is generated. In an LHB #4 section of the frame #1, ahorizontal synchronization signal can be generated such that ahorizontal time of VH1_4 period is generated. In an LHB #5 section ofthe frame #1, a horizontal synchronization signal can be generated suchthat a horizontal time of VH1_5 period is generated. In an LHB #6section of the frame #1, a horizontal synchronization signal can begenerated such that a horizontal time of VH1_6 period is generated. Inan LHB #7 section of a frame #1, a horizontal synchronization signal canbe generated such that a horizontal time of VH1_7 period is generated.In an LHB #8 section of a frame #1, a horizontal synchronization signalcan be generated such that a horizontal time of VH1_8 period isgenerated. For example, a horizontal time VH1_1 of LHB #1 can bedifferent than a horizontal time VH1_2 of LHB #2.

According to another embodiment, a period of a horizontal time can beset to be changed for each two consecutive LHB sections in each framesection (e.g., the next two consecutive LHB sections can be made longeror shorter than the previous two consecutive LHB sections). For example,a horizontal time of LHB #1 and LHB #2 can be VH1_1. A horizontal timeof LHB #3 and LHB #4 can be VH1_2. As a result, LHB #1 and LHB #2 canhave same horizontal time (VH1_1). LHB #3 and LHB #4 can have samehorizontal time (VH1_2). LHB #1 and LHB #2 can have a horizontal time(VH1_1) which is different than a horizontal time (VH1_2) of LHB #3 andLHB #4.

Referring to the example in FIG. 3 , in an LHB #1 section and an LHB #2section of a frame #2, a horizontal synchronization signal can begenerated such that a horizontal time of VH2_1 period is generated. Inan LHB #3 section and an LHB #4 section of the frame #2, a horizontalsynchronization signal can be generated such that a horizontal time ofVH2_2 period is generated. In an LHB #5 section and an LHB #6 section ofthe frame #2, a horizontal synchronization signal can be generated suchthat a horizontal time of VH2_3 period is generated. In an LHB #7section and an LHB #8 section of the frame #2, a horizontalsynchronization signal can be generated such that a horizontal time ofVH2_4 period is generated. According to still another embodiment, aperiod of a horizontal time can be set to be changed for each three orfour consecutive LHB sections in each frame section (e.g., after threeor four consecutive LHB sections, the horizontal time period can bechanged or made different for the next three or four consecutive LHBsections). According to yet another embodiment, all horizontal timegenerated in the frame #1 can have the same period, and all horizontaltime generated in the frame #2 can have the same period. However, theperiod of the horizontal time in the frame #1 and the period of thehorizontal time in the frame #2 can be different from each other (e.g.,shorter or longer). The examples described above are merely embodiments,and the period of the horizontal times can be different from each otherdepending on settings of the other sections.

The period of the horizontal time for each LHB section can be changed invarious manners. According to an embodiment, each time the LHB sectionis changed, the period of the horizontal time of the corresponding LHBsection can be set to be increased by a constant size (e.g., the periodof the horizontal time of each subsequent LHB section made longer by aconstant amount, such as by adding an additional 0.167 us each time)from the period of the horizontal time of the previous LHB section. Theperiod of the horizontal time of the corresponding LHB section can beset to be decreased by a constant size after reaching the maximumsettable period. According to another embodiment, the minimum andmaximum values of the period of the horizontal time that the LHB sectioncan have can be set in advance. Or the period of the horizontal time ofthe corresponding LHB section can be set randomly by selecting a valuefrom between the minimum value and the maximum value.

Table 1 illustrates an example of setting of the period of thehorizontal time that will be generated for each LHB section of eachframe, and Table 2 and Table 3 illustrate examples of horizontal timevalues that a setting variable VHx_y can have.

TABLE 1 Frame#1 Frame#2 Frame#3 LHB#1 VH1_1 VH2_1 VH3_1 LHB#2 VH1_2VH2_2 VH3_2 LHB#3 VH1_3 VH2_3 VH3_3 LHB#4 VH1_4 VH2_4 VH3_4 LHB#5 VH1_5VH2_5 VH3_5 LHB#6 VH1_6 VH2_6 VH3_6 LHB#7 VH1_7 VH2_7 VH3_7 LHB#8 VH1_8VH2_8 VH3_8 LHB#9 VH1_9 VH2_9 VH3_9 LHB#10 VH1_10 VH2_10 VH3_10 LHB#11VH1_11 VH2_11 VH3_11 LHB#12 VH1_12 VH2_12 VH3_12

TABLE 2 VHx_y Setting value 3′b000 17.099 us 3′b001 17.266 us 3′b01017.433 us 3′b011 17.600 us 3′b100 17.767 us 3′b101 17.934 us 3′b11018.101 us 3′b111 18.268 us

TABLE 3 VHx_y Setting value 5′b00000 17.099 us 5′b00001 17.141 us5′b00010 17.183 us 5′b00011 17.224 us 5′b00100 17.266 us . . . . . .5′b01001 17.475 us 5′b01010 17.517 us 5′b01011 17.558 us 5′b01100 17.600us . . . . . . 5′b10100 17.934 us 5′b10100 to 5′b11111 Disabled

As illustrated in Table 1, the number of LHB sections in one framesection can be set, and accordingly, a register capable of setting theperiod of the horizontal time for each LHB section of each frame can beprovided. Each register can have horizontal time period information of aspecific LHB section of a specific frame section. According to anembodiment, the number of repeated frames can be determined. Asillustrated in an example in Table 1, when the number of repeated framesis determined to be three, the same horizontal time can be repeated forevery third frame. Therefore, it can be sufficient to be provided withthe number of registers enough to set the period of the horizontal timefor each LHB section for each of the three frames. Accordingly, thesetting of the horizontal time period used in the frame #1 can beequally used in a frame #4.

In addition, according to an embodiment, two consecutive LHB sectionscan be set to have the same period of horizontal time by setting VH1_2to the same value of the VH1_1, by setting the VH1_4 to the same valueof the VH1_3, by setting the VH1_6 to the same value of the VH1_5, bysetting the VH1_8 to the same value of the VH1_7, by setting the VH1_10to the same value of the VH1_9, and by setting the VH1_12 to the samevalue of the VH1_11. The period of the horizontal time generated at eachLHB section of each frame can vary depending on the setting.

When each register is formed of three bits, eight horizontal timeperiods as illustrated in the example in Table 2 can be set. For anexample, when “000” is written to the VH1_1 of Table 1, the period ofthe horizontal time that is generated at the LHB #1 section of the frame#1 can be 17.099 us.

According to another embodiment, when each register is formed of fivebits, a maximum of 32 horizontal time periods as illustrated in Table 3can be set. When some bit values are not used, less than 32 horizontaltime periods can be set. Comparing Table 2 and Table 3, the more bitseach register has, the more detailed horizontal time period settable canbe realized.

FIG. 4 is a view illustrating an example of generating the horizontaltimes having different periods from each other according to variousembodiments of the present disclosure.

Referring to FIG. 4 , the display device 100 can perform displaying byusing 720 gate lines. In addition, the frame can be divided into eightLHB sections. Then, in each LHB section, 90 gate lines can be controlledand 90 gate signals can be generated. Then, in the LHB #1 section, thehorizontal time period can be 17.099 us as the VH1_1 is set to 5′b00000.In the LHB #2 section, the horizontal time period can be 17.266 us asthe VH1_2 is set to 5′b01010. In the LHB #3 section, the horizontal timeperiod can be 17.433 us as the VH1_3 is set to 5′b10100 (e.g., thetiming for controlling one gate line can be increased by 0.167 us duringeach subsequent LHB section).

FIG. 5 is a view illustrating a circuit related to the generation of ahorizontal synchronization signal for forming a variable periodhorizontal time according to various embodiments of the presentdisclosure.

Referring to FIG. 5 , the timing controller 140 can generate ahorizontal synchronization signal for each LHB section of each frame ina horizontal synchronization signal generator 510. According to anembodiment of the present disclosure, the horizontal synchronizationsignal generator 510 can acquire horizontal time period information froma horizontal time period register 520. The horizontal time periodinformation for each LHB section for each frame is generated based on acurrent frame and a current LHB section. The horizontal synchronizationsignal generator 150 can generate a horizontal synchronization signalbased on the corresponding horizontal time period information.

The generated horizontal synchronization signal is transmitted to atouch-enable generator 530. The touch-enable generator 530 can generatea touch-enable signal based on the horizontal synchronization signal.

The generated touch-enable signal is transmitted to multiplexers MUXs541, 543, and 545, and can control whether to transmit a source data tothe data line or to transmit a touch driving signal to the data line. Inaddition, the touch-enable signal can control whether to output a Vcomvoltage to the touch electrode TE or to output the touch driving signalto the touch electrode TE. The touch-enable signal can be used todetermine whether to output the gate signal to the gate line or tooutput the touch driving signal to the gate line. According to anembodiment, the Vcom voltage can be a Vcom voltage generally referred toin a liquid crystal display, but is not limited thereto. According to anembodiment, a first multiplexer 541 can be provided at the data driver130 through a data line DL, a second multiplexer 543 can be provided atthe touch driver 150 through a touch line TL, and a third multiplexer545 can be provided at the gate driver 120 through a gate line GL.

According to an embodiment, a data-enable signal represents whether thedata transmitted from the timing controller 140 to the data driver 130is valid. In order to generate a data-enable signal, a counter can beused to count from zero to nine within a horizontal time section.However, when the horizontal time section becomes longer, the countercan malfunction when the counter counts ten instead of being initializedto zero after counting nine. In order to solve this problem of avariable horizontal time section, a circuit can be configured such thatthe counter is initialized to zero every time after the counter reachesnine.

In FIG. 5 , an example of determining the period of the horizontal timethat will be used in each LHB section by using the horizontal timeperiod register 520 is illustrated. However, the period of thehorizontal time that will be used in each LHB section can be determinedwithout using the horizontal time period register 520.

According to an embodiment, each time the LHB section is changed, theperiod of the horizontal time of the corresponding LHB section can beset to be increased by a constant size from the period of the horizontaltime of the previous LHB section (e.g., increase by 0.167 us). Theperiod of the horizontal time of the corresponding LHB section also canbe set to be decreased by a constant size after reaching the maximumsettable period. According another embodiment, the minimum and maximumvalues of the period of the horizontal time that the LHB section canhave can be set in advance. Or the period of the horizontal time of thecorresponding LHB section can be set randomly by selecting a value frombetween the minimum value and the maximum value. The LHB section can beset to have a randomly selected horizontal time period, but the LHBsection can be set to have a predetermined horizontal time period thatis selected from among a plurality of different predetermined horizontaltime periods.

FIG. 6 is a view illustrating examples of determining a horizontal timeperiod by a method other than using a horizontal time period register inFIG. 5 , in which the horizontal time period will be used in each LHBsection.

The timing controller 140 can store different available horizontal timeperiods in correspondence with an index as shown in Table 2. Forexample, as shown in Table 2, the horizontal time period of 17.099 us incorrespondence with index 0 (3′b000), the horizontal time period of17.767 us in correspondence with index 4 (3′b100), and the horizontaltime period of 18.268 us in correspondence with index 7 (3′b111) can bestored. In addition, the timing controller 140 can acquire a new indexeach time the LHB section is changed, and the horizontal time period incorrespondence with the acquired index can be used in the correspondingLHB section.

Referring to FIG. 6 , as a method of changing the index, the timingcontroller 140 can increase the index sequentially by one entry or spotas illustrated in (a) (e.g., in the form of a look-up table). Or thetiming controller 140 can increase the index sequentially by two orthree entries at a time as illustrated in (b) or (c). At this time, aremainder function can be used. That is, a remainder acquired bydividing the increased index by the number of stored horizontal timeperiods can be used as a new index. According to another embodiment, thetiming controller 140 can use a random function to determine the indexas illustrated in (d). According to still another embodiment, asillustrated in (e), the timing controller 140 can increase the indexsequentially by one, and then decrease the index sequentially by onewhen the index is at the highest value thereof (for example, 3′b111).

FIG. 7 is a view illustrating a method of generating the variable periodhorizontal time by a timing controller, according to various embodimentsof the present disclosure.

Referring to FIG. 7 , in an operation S100, the timing controller 140can set the period of the available horizontal time. According to anembodiment, the timing controller 140 can set the period of theavailable horizontal time as shown in Table 2 or Table 3.

In an operation S200, the timing controller 140 can determine the numberof LHB sections in one frame. According to an embodiment, the timingcontroller 140 can determine the number of LHB sections in the frame tobe an arbitrary number such as 8, 10, 12, 16, or the like.

In an operation S300, the timing controller 140 can set the horizontaltime period to be used for each MB section in the frame (e.g., thehorizontal time period can correspond to the timing for one pulse or onecycle of the Hsync signal used for controlling gate lines). According toan embodiment, the horizontal time period to be used for each LHBsection can be set by selecting one of the available horizontal timeperiods set in the operation S100.

In addition, in the operation S200, the timing controller 140 candetermine the number of repeated frames. According to an embodiment, thetiming controller 140 can determine the number of repeated frames to ben, where n is a positive integer. Then, in the operation S300, thehorizontal time period to be used for each LHB section for n frames canbe set. Then, the horizontal time period at each MB section of a firstframe can be the same as the horizontal time period at the correspondingLHB section of an n+1th frame (e.g., the pattern can be repeated overagain starting at an n+1th frame).

According to another embodiment, in the operation S300, the timingcontroller 140 can use the horizontal time period to be used in each LHBsection by changing the available horizontal time period set in theoperation S100 one by one in the new LHB.

For example, in the operation S100, eight horizontal time periods shownin Table 2 can be set. The set horizontal time periods available in theLHB sections can be stored in correspondence with an index as shown inTable 2.

In the operation S200, the number of LHB sections in the frame can bedetermined to be 10.

Then, in the operation S300, the timing controller 140 can change theindex each time the LHB section is changed, and can use the horizontaltime period that corresponds to the changed index to generate ahorizontal synchronization signal at the corresponding LHB section(e.g., in a look-up table manner). According to an embodiment, thetiming controller 140 can increase the index sequentially by one, or canincrease the index sequentially by two or three at a time. At this time,a remainder function can be used. That is, a remainder acquired bydividing the increased index by the number of stored horizontal timeperiods can be used as a new index. According to another embodiment, thetiming controller 140 can use a random function to determine the index.According to still another embodiment, the timing controller 140 canincrease the index sequentially by one, and then decrease the indexsequentially by one when the index is at the highest value thereof (forexample, 3′b111, and using a pattern that ramps up and then ramps down).

According to an example of sequentially increasing the index by one, afirst LHB section of a first frame can be set to have a horizontal timeperiod corresponding to 3′b000. A second LHB section of the first framecan be set to have a horizontal time period corresponding to 3′b001. Athird LHB section of the first frame can be set to have a horizontaltime period corresponding to 3′b010. A fourth LHB section of the firstframe can be set to have a horizontal time period corresponding to3′b011. A fifth LHB section of the first frame can be set to have ahorizontal time period corresponding to 3′b100. A sixth MB section ofthe first frame can be set to have a horizontal time periodcorresponding to 3′b101. A seventh LHB section of the first frame can beset to have a horizontal time period corresponding to 3′b110. An eighthLHB section of the first frame can be set to have a horizontal timeperiod corresponding to 3′b111. Then, by starting again from thebeginning, a ninth LHB section of the first frame can be set to have ahorizontal time period corresponding to 3′b000, and a tenth LHB sectionof the first frame can be set to have a horizontal time periodcorresponding to 3′b001. Then, a first LHB section of a second framethat is a next frame can be set to have a horizontal time periodcorresponding to 3′b010.

According to another embodiment of changing the index in a pattern inwhich the index is increased by one and then decreased by one afterreaching the maximum value in order to prevent a large change in thehorizontal time period between neighboring LHB sections (e.g., rampingup and then ramping down), a ninth LHB section of a first frame can beset to have a horizontal time period corresponding to 3′b110 instead of3′b000. Further, a tenth LHB section of the first frame can be set tohave a horizontal time period corresponding to 3′b101. Then, a first LHBsection of a second frame that is a next frame can be set to have ahorizontal time period corresponding to 3′b100.

In operation S400, the timing controller 140 can generate a horizontalsynchronization signal to allow each LHB section to have a sethorizontal time period.

Operations described in FIG. 7 illustrate a method of selecting ahorizontal time period from preset horizontal time periods, but thehorizontal time period can be set randomly.

According to an embodiment, each time the LHB section is changed, thehorizontal time period of corresponding LHB section can be set to beincreased by a constant size relative to the horizontal time period ofthe previous LHB section, and can be set to be decreased by a constantsize after reaching the maximum settable period. Here, the increasingsize and the decreasing size can be different from each other. Accordingto another embodiment, the minimum and maximum values of the horizontaltime period that the LHB section can have can be set in advance, and thehorizontal time period of the LHB section can be set randomly byselecting a value from between the minimum value and the maximum value.

As described above, in the method and the apparatus proposed in thepresent specification, EMI noise can be mitigated by changing ahorizontal synchronization signal having a constant cycle to have avariable cycle that can change from LHB section to LHB section.

What is claimed is:
 1. A display device comprising: a display panelincluding a plurality of pixels and touch electrodes configured to sensea touch input; and a timing controller configured to: generate avertical synchronization signal and a horizontal synchronization signalfor controlling the display panel to display an image based on an imagesignal, and adjust the horizontal synchronization signal by varying ahorizontal time period corresponding to a time period interval forindividual cycles of the horizontal synchronization signal, wherein aframe section between a start of one cycle of the verticalsynchronization signal and a start of a next cycle of the verticalsynchronization signal comprises a plurality of long horizontal blank(LHB) sections, each of the plurality of LHB sections including adisplay driving section for controlling the display panel to display theimage signal based on the horizontal synchronization signal and a touchdriving section for controlling a touch driving signal to be sent to thetouch electrodes of the display panel, and wherein the timing controlleris further configured to adjust the horizontal synchronization signal toset at least some of the plurality of LHB sections to have horizontaltime periods that are different from each other.
 2. The display deviceof claim 1, wherein the timing controller is further configured toadjust the horizontal synchronization signal to set at least some of theplurality LHB sections provided in a plurality of frame sections to havehorizontal time periods that are different from each other.
 3. Thedisplay device of claim 1, wherein the timing controller is furtherconfigured to: determine a horizontal time period of a changed LHBsection by adding a first predetermined amount of time to a horizontaltime period used in a previous LHB section, or by subtracting a secondpredetermined amount of time from the horizontal time period used in theprevious LHB period.
 4. The display device of claim 1, wherein thetiming controller is further configured to: determine a horizontal timeperiod of a changed LHB section by randomly selecting an amount of timefor the horizontal time period for the changed LHB section that isbetween a predetermined minimum horizontal time period and apredetermined maximum horizontal time period, the predetermined maximumhorizontal time period being an amount of time that is longer than thepredetermined minimum horizontal time period.
 5. The display device ofclaim 1, wherein the timing controller comprises: a horizontal timeperiod register configured to store horizontal time period informationfor at least one of the plurality of LHB sections; and a horizontalsynchronization signal generator configured to generate the horizontalsynchronization signal based on the horizontal time period informationstored in the horizontal time period register.
 6. The display device ofclaim 5, further comprising: a data driver configured to output a datasignal to each of a plurality of data lines of the display panel; a gatedriver configured to output a gate signal to each of a plurality of gatelines of the display panel; and a touch driver configured to provide atouch driving signal to the touch electrodes of the display panel,wherein the timing controller further comprises a touch-enable generatorconfigured to generate a touch-enable signal that indicates the displaydriving section and the touch driving section based on the horizontalsynchronization signal generated by the horizontal synchronizationsignal generator, wherein the data driver outputs the data signal andthe touch driving signal to the plurality of data lines based on thetouch-enable signal, wherein the touch driver outputs a common voltageor the touch driving signal to the touch electrodes based on thetouch-enable signal, and wherein the gate driver outputs the gate signaland the touch driving signal to the plurality of gate lines based on thetouch-enable signal.
 7. The display device of claim 1, wherein thetiming controller comprises: a register configured to store availablehorizontal time periods in correspondence with an index; and ahorizontal synchronization signal generator configured to: select adifferent entry in the index each time one of the plurality of LHBsections is changed, acquire a horizontal time period received from theregister based on the different entry selected from the index, andgenerate the horizontal synchronization signal based on informationrelated to the horizontal time period received from the register.
 8. Thedisplay device of claim 7, wherein the horizontal synchronization signalgenerator is further configured to change the index to a new index, thenew index being a remainder acquired by increasing the index by anatural number and dividing the index by a number of availablehorizontal time periods.
 9. The display device of claim 7, wherein thehorizontal synchronization signal generator is further configured toselect entries in the index by traversing the index in a pattern thatramps up to a maximum value and then ramps down from the maximum value.10. A method of controlling a touch display device, the methodcomprising: generating, by a timing controller in the touch displaydevice, a vertical synchronization signal and a horizontalsynchronization signal for controlling a display panel in the touchdisplay device to display an image based on an image signal; adjusting,by the timing controller, the horizontal synchronization signal byvarying a horizontal time period corresponding to a time period intervalfor individual cycles of the horizontal synchronization signal; anddividing a frame section into a plurality of long horizontal blank (LHB)sections, each of the plurality of LHB sections including a displaydriving section for controlling the display panel to display the imagesignal based on the horizontal synchronization signal and a touchdriving section for controlling a touch driving signal to be sent totouch electrodes of the display panel, wherein the adjusting thehorizontal synchronization signal includes setting at least some of theplurality of LHB sections to have horizontal time periods that aredifferent from each other.
 11. The method of claim 10, wherein theadjusting the horizontal synchronization signal comprises: determining ahorizontal time period of a changed LHB section by adding a firstpredetermined amount of time to a horizontal time period used in aprevious LHB section, or by subtracting a second predetermined amount oftime from the horizontal time period used in the previous LHB period;and adjusting the horizontal synchronization signal to set the changedLHB section to have the determined horizontal time period.
 12. Themethod of claim 10, wherein the adjusting the horizontal synchronizationsignal comprises: determining a horizontal time period of a changed LHBsection by randomly selecting an amount of time for the horizontal timeperiod for the changed LHB section that is between a predeterminedminimum horizontal time period and a predetermined maximum horizontaltime period, the predetermined maximum horizontal time period being anamount of time that is longer than the predetermined minimum horizontaltime period; and adjusting the horizontal synchronization signal to setthe changed LHB section to have the determined horizontal time period.13. The method of claim 10, further comprising: setting horizontal timeperiod information for controlling plurality of LHB sections, whereinthe adjusting the horizontal synchronization signal includes varying thehorizontal time periods based on the horizontal time period information.14. The method of claim 10, further comprising: storing horizontal timeperiod information for at least one of the plurality of LHB sections ina horizontal time period register; and generating, by a horizontalsynchronization signal generator in the touch display device, thehorizontal synchronization signal based on the horizontal time periodinformation stored in the horizontal time period register.
 15. Themethod of claim 10, further comprising: outputting a data signal to eachof a plurality of data lines of the display panel; outputting a gatesignal to each of a plurality of gate lines of the display panel;providing a touch driving signal to touch electrodes in the touchdisplay device; and generating a touch-enable signal, by a touch-enablegenerator in a timing controller, that indicates the display drivingsection and the touch driving section based on the horizontalsynchronization signal generated by a horizontal synchronization signalgenerator, wherein the data signal and the touch driving signal areoutput to the plurality of data lines based on the touch-enable signal,wherein a common voltage or the touch driving signal is output to thetouch electrodes based on the touch-enable signal, and wherein the gatesignal and the touch driving signal are output to the plurality of gatelines based on the touch-enable signal.
 16. The method of claim 10,further comprising: storing, in a register in the touch display device,available horizontal time periods in correspondence with an index;selecting, by a horizontal synchronization signal generator in the touchdisplay device, different entry in the index each time one of theplurality of LHB sections is changed; acquiring a horizontal time periodreceived from the register based on the different entry selected fromthe index; and generating the horizontal synchronization signal based oninformation related to the horizontal time period received from theregister.
 17. The method of claim 16, further comprising: changing theindex to a new index, wherein the new index is a remainder acquired byincreasing the index by a natural number and dividing the index by anumber of available horizontal time periods.
 18. The method of claim 17,further comprising: selecting entries in the index by traversing theindex in a pattern that ramps up to a maximum value and then ramps downfrom the maximum value.